1. Field of the Invention
Present invention relates to microwave hybrid tee junctions connected in combination and particularly to such combinations in which the symmetrical arms are used for output connections in power combining and nonsymmetrical arms are used for output connecting in power dividing.
2. Description of the Prior Art
Magic tees, because of their plane of symmetry, are usually used as power dividers with the e or h ports as the input and the symmetrical ports as the two outputs. This is the most natural way to use the tees since the output phase relationships are a clear 0 or 180 degrees, and the output equality is essentially perfect. The tees are also often used as power combiners in which case the preferred choice for the two inputs is the symmetrical ports since the input phase and split requirements are clearly defined and easily realized. Previous U.S. Pat. No. 3,931,599 of the present inventor describes hybrid tee junction combinations with the e and h plane arms providing input, output functions. It has been considered undesirable to use a magic tee as a power divider with the e and h ports as outputs since it is difficult to obtain equal split in the output and the output phase may track at some odd angle. It is also uncommon to use the symmetrical ports as outputs for a power combiner because of an apparent difficulty in meeting the required input phases and amplitude requirements to get precise power combination.
Technical Bulletin No. 020774-1 of Electromagnetes Sciences Inc., Chamblee, Ga., describes a power modulator in which a magic tee is used as a power divider and the power out is connected through the symmetrical arms to two phase shifters which drive a quadrature coupler. If one of the phase shifters is switched 180.degree., the output will change terminals and shift 90.degree. in phase. The outputs of the quadrature coupler will always be 180.degree. out of phase with each other.